Calcitriol versus Cholecalciferol on Biochemical Markers of Metabolic Bone Disease in Very Low Birth Weight Infants: A Randomized Clinical Trial

About 55% of extremely-low-birth-weight (birth weight < 1000 g) and 23% of very low-birth-weight infants (birth weight < 1500 g) suffer from metabolic bone disease (MBD). There are limited data on the use of calcitriol (1, 25-dihydroxycholecalciferol) to prevent or treat MBD in preterm infants. Therefore, this study aimed to compare the preventive effect of calcitriol and cholecalciferol on the biochemical markers of MBD in preterm infants.

This study was a pilot randomized controlled trial conducted in the Alzahra teaching hospital of Tabriz University of Medical Sciences. we randomized 72 very-low-birth-weight infants in two groups of calcitriol 0.25 μg/day and cholecalciferol 400 IU/day. Biochemical markers, including serum 25-hydroxyvitamin D, alkaline phosphatase (ALP), phosphorus (P),calcium (Ca), parathyroid hormone (PTH), and tubular reabsorption of phosphate (TRP) levels were checked at baseline, three, and five weeks after medication, consecutively.

After three weeks of supplementation, infants in the cholecalciferol group had higher levels of serum 25-hydroxyvitamin D (P=0.001) and lower levels of urine phosphate (P=0.009); There were no significant differences in other biochemical markers. At the end of the fifth week, there was no significant difference between the two groups in terms of biochemical markers.

The study indicated that the use of cholecalciferol caused a lower urinary loss of phosphate in very-low birth-weight infants at a short time; however, these findings were not sustained during the study period.